/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.pinot.core.segment.processing.transformer;

import java.util.HashMap;
import java.util.Map;
import org.apache.pinot.segment.local.function.FunctionEvaluator;
import org.apache.pinot.segment.local.function.FunctionEvaluatorFactory;
import org.apache.pinot.spi.data.readers.GenericRow;


/**
 * RecordTransformer which executes transform functions to transform columns of record
 * Does not follow any particular order, and hence cannot support transformations where strict order of execution is
 * needed
 */
public class TransformFunctionRecordTransformer implements RecordTransformer {

  private final Map<String, FunctionEvaluator> _functionEvaluatorMap = new HashMap<>();

  public TransformFunctionRecordTransformer(Map<String, String> transformFunctionMap) {
    transformFunctionMap.forEach(
        (key, value) -> _functionEvaluatorMap.put(key, FunctionEvaluatorFactory.getExpressionEvaluator(value)));
  }

  @Override
  public GenericRow transformRecord(GenericRow row) {
    for (Map.Entry<String, FunctionEvaluator> entry : _functionEvaluatorMap.entrySet()) {
      Object result = entry.getValue().evaluate(row);
      row.putValue(entry.getKey(), result);
    }
    return row;
  }
}
